Low fat spread

ABSTRACT

A water-continuous spread containing from 0.1 to 20 wt. % of fat, said spread being a W/O/W emulsion comprising hydrolysed starch with a DE of 1-6 in the external phase at a concentration above its critical gelling concentration, said spread having a stress strain relation with a maximum stress occurring at a strain of 0.001-1, the maximum stress at this strain being 0.01 to 100 kPa and with a ratio of plastic stress and the maximum stress of 0.1 to 1.

The present invention is concerned with spread products, in particularwith spread products having a continuous waterphase of low fat content,and processes for their preparation.

BACKGROUND OF THE INVENTION

Many attempts have been made to formulate fat-continuous low fat spreadproducts. Amongst the various reasons why such products are desired isthe wish to reduce the caloric content of the spread and other dieteticconsiderations and to a minor extent the wish to lower the productioncosts, in particular by reducing the raw material costs.

A substance that has widely been applied as a fat extender is water.This use of water has, for example, led to the introduction of so-calledhalvarines. If relatively high levels of water are used, oftenthickening agents and/or gelling agents are used for avoiding adverseeffects of the high water level.

For example EP 298 561 (Unilever N.Y.) describes the preparation ofedible plastic dispersions not having a continuous fat phase, saidcomposition including at least two gelling agents forming twogel-forming compositions.

U.S. Pat. No. 4,869,916 (Kuniaki Inayoshi et al) discloses a "whippedoily flavor" containing more than 5% of oil with a 100% overrun whichcan be in the form of W/O/W-emulsion containing at least 7% of alow-sweet saccharide as e.g. maltodextrin so as to provide a freezeresistance to the final product and an emulsifier like polyglycerolricinoleic acid ester. From the fact that the intermediate emulsion iswhipped to an overrun of about 100% it can be deduced that theintermediate emulsion before whipping must be low viscous and not in theform of a plastic gel which teaches away from the use of a gellingmaltodextrin above its critical concentration. Also the fact thatmaltodextrin is used as a protection against freezing suggests stronglythat the maltodextrin used has a low average molecular weight andconsequently a high DE (Dextrose Equivalent) because this results in ahigher freezing point depression at a given weight quantity of low-sweetsugar. Consequently U.S. Pat. No. 4,869,916 points away from the use ina W/O/W emulsion of a gelling hydrolysed starch c.q. maltodextrin with ahigher average molecular weight and lower DE i.e. from about 1-6 andabove its critical gelling concentration.

SUMMARY OF THE INVENTION

It is the object of the present invention to formulate water-continuous,(very) low fat spread products having an improved flavour release,appearance, texture, mouthfeel and/or rheology. Surprisingly it has beenfound that these high quality, low fat products can be obtained ifspecific levels of fat are used and the spread has a specific threephase structure.

Accordingly the present invention provides a water-continuous spreadcontaining from 0.1 to 20 wt. % of fat, said spread being a W/O/Wemulsion comprising hydrolysed starch with a DE of about 1-6 in theexternal phase at a concentration above its critical gellingconcentration, said spread having a stress strain relation with amaximum stress occurring at a strain of 0.01-1, the maximum stress atthis strain being 0.1 to 100 Kpa and with a ratio of plastic stress andthe maximum stress of 0.1 to 1. Compositions of the invention comprisetwo aqueous phases: a continuous external water phase, containing a fatphase dispersed therein and an internal aqueous phase dispersed in saidfat phase.

DESCRIPTION OF THE PREFERRED EMBODIMENTS

Preferably the dispersed phases (fat phase plus internal aqueous phasedispersed in the fat phase) constitute from 1 to 80 wt % of the product,more preferred 2 to 50 wt %, most preferred 3 to 30 wt %. Within thedispersed phases the weight ratio of fat to water is preferably from50:1 to 1:50, more preferred 2:1 to 1:30, most preferred 1:1 to 1:20.

The external aqueous phase preferably constitutes from 20 to 99 wt %,more preferred 50-98 wt %, most preferred 70 to 97 wt % of the product.

According to an embodiment of the invention the external aqueous phaseis gelled or thickened. This can be accomplished by incorporatinggelling or thickening agents, preferably gelling hydrolysed starch and agelling agent, especially gelatin, in the composition e.g. at a level offrom 0.1 to 30 wt % taken together. Of course the level should exceedthe critical gelling concentration, but on the other hand the maximumsolubility should not be exceeded. Any commercially available gelatinmay be used, although it is preferred to have a gelatin having a bloomstrength between 100 and 300, such as 120, 150 and 250. Especiallypreferred is the use of gelatin having a bloom strength of about 200 to270.

Especially preferably, compositions of the invention contain from 0.5 to20 wt % of thickening or gelling biopolymer materials, for examplegelling starches, gums or proteins. The biopolymers may be added as suchor may for example be included in the form of commercially availablefat-replacers.

The preferred levels of biopolymers for obtaining optimum productproperties (e.g. plasticity and/or non-thixotropy), generally alsodepend on the type of biopolymer used. Also the preferred amount ofbiopolymers is dependant on the desired degree of thickening or gellingand the presence of other ingredients in the composition.

If gums or thickening polysaccharides other than gelling starches areused, their preferred level is 0.1 to 5 wt %, more preferred 0.15 to 3wt %, most preferred 0.2 to 2 wt %. Suitable gums may for example beselected from the group of agar, alginate, gum arabic, carrageenan,furcelleran, ghatti, guar, karaya, latch, locust bean, pectin,tragacanth and xanthan gum. Especially preferred is the use of agar,carrageenan, furcelleran, guar, locust bean, pectin and xanthan gum.Most preferred is the use of locust bean, pectin and xanthan gum. Theterm pectin also includes calcium sensitive pectins and modified pectinssuch as amidated pectins etc. Also preferably the biopolymers may beincorporated by including commercially available fat-replacers based ongums, for example Slimgel™ (powder from a phase separated mixture ofgelatin and guar or locust bean gum) and Veri-Lo™ (an oil in wateremulsion stabilized by emulsifiers and embedded in sheared agarparticles). Also preferably sheared thermoreversible polysaccharide gelsor sheared chemically set polysaccharide gels may be used such as forexample disclosed in EP-A-355 908 or EP-A-432 835.

If starches are used as biopolymer material, preferably gelling starchesare used. It is preferred to use hydrolysed starches with a DE (DextroseEquivalent) of 1 to 6, most preferably from 2 to 4. Especially preferredis the use of gelling modified starches/maltodextrins, for examplehydrolysed starches such as Paselli SA2 (AVEBE), N-oil (National Starch& Chemical Corp.), and microcrystalline cellulose. Also commerciallyavailable fat-replacers which are based on such biopolymer materials maybe used, for example Stellar™ (a starch based powder from cornmaltodextrin), Trailblazer™ (coacervate of a protein + polysaccharidecomplex, such as egg albumin and xanthan gum) and Raftilene™ LS(inulin). The level of (modified) starches is preferably 5 to 20 wt %,more preferred 6 to 17 wt %, most preferred 7 to 15 wt %; if themodified starches are used in combination with other biopolymermaterials, their level may be lower for example 0.05 to 10 wt %.

If proteins are used as biopolymer material, preferably proteins areused as disclosed in EP 237 120. Examples of suitable materials aregelatin, storage protein e.g. soy protein, milk protein, sodiumcaseinate etc. Especially preferred is the use of gelling proteins, mostpreferred is the use of gelatin. The level of (gelling) proteins ispreferably from 0.5 to 10 wt %, more preferred 0.7 to 7 wt %, mostpreferred 0.9 to 5 wt %. Also commercially available fat replacers basedon these materials may be used for example Simplesse™ (dispersion ofmicroparticulated whey protein or egg white particles) or Dairy-Lo™. Theuse of gelling agents often in conjunction with a thickening agent isespecially important in the external water phase.

Especially preferably, compositions of the invention contain at leasttwo biopolymer materials, each being present at a level from 0.1 to 20wt %. For a very good rheology these two biopolymer materials arepreferably capable of forming two gelled aqueous phases which togetherform the external aqueous phase.

The critical gelling concentration of a gelling agent is theconcentration level at which said gelling agent will start to form agel. The critical gelling concentration of a gelling agent in aparticular composition can be calculated from measurements of the shearmodulus of a series of samples containing different concentrations of agelling agent as described in Br. Polymer J. 17, (1985) 164. If thecritical concentration of a combination of gelling agents is to bedetermined, then the critical concentration of such mixture of gellingagents is determined in a manner analogous to the procedure describedabove.

Compositions of the invention comprise from 0.1 to 20 wt % of fat, morepreferred the level of fat is more than 0.5 wt % and less than 15 wt %,most preferred are fat levels from 1 to 10 wt %.

Compositions of the invention preferably also comprise an emulsifiersystem in a level up to 5 wt % (more preferably 0.01 to 3 wt %) on totalproduct, more preferably the emulsifier system comprises both anoil-in-water (o/w) emulsifier and a water-in-oil (w/o) emulsifier. Avery efficient w/o emulsifier is Admul WOL (e.g. polyglycerol ester ofpolyricinolenic acid) and an good o/w emulsifier is e.g. sodiumcaseinate. The amount of emulsifiers used depends inter alia on theamount of water in the spread and the nature of the emulsifier.Preferably the amount of w/o emulsifier ranges between 0.05 to 2 wt % ontotal product and the amount of o/w emulsifier between 0.5 and 1 wt %.Most preferable the weight ratio w/o to o/w emulsifiers ranges from 2:1to 1:10 whereby the former relates to products with a high internalphase content and the latter relates to products with a low internalphase content.

Throughout this specification the terms oil and fat are usedinterchangeably. They are meant to include triglycerides of natural orsynthetic origin such as soybean oil, sunflower oil, palm oil, fish oil,rapeseed oil, coconut oil, and hydrogenated, fractionated and/orinteresterified triglyceride mixtures as well as edible substances thatare physically similar to triglycerides such as waxes, e.g. jojoba oiland poly fatty acid esters of mono- or disaccharides, and that can beused as replacement for or in admixture with triglycerides. Preferably,vegetable oils are used, which are liquid, at 5° C.

In an embodiment of the invention spreads are provided in which the fatphase is based on highly unsaturated vegetable oils as e.g. sunfloweroil, low-erucic rapeseed oil, soya bean oil etc.

It is important that spreads of the invention are plastic in the sensethat they can be spread onto bread without tearing the bread. Generallyplastic spreads will have a stress strain relation with a maximum stressoccurring at strain of 0.01-1 (preferably 0.1 to 0.3), the maximumstress at this strain being 0.01-100 Kpa (preferably 0.1 to 50 Kpa) andwith a ratio of plastic stress and the maximum stress of 0.1 to 1,preferably above 0.5. A suitable method for determining these values isgiven in EP-A-298 561.

In addition to the above mentioned ingredients, spreads of the inventionmay comprise a number of optional ingredients such as flavouring, salt,preservatives, acidifiers, vitamins, colouring materials etc.

Preferably the level of flavouring materials is 0.01 to 2 wt %.Preferably, the level of salt (sodium chloride) is from 0-4 wt %, morepreferred 0.1 to 3 wt %, most preferred 0.3 to 1.5 wt %. Preservativesare preferably incorporated at a level of 0-4 wt %, more preferred 0.01to 1 wt %, most preferred 0.05 to 0.3 wt %. Especially preferred is theuse of potassium sorbate. A preferred colouring material is β-carotene;preferred levels of colouring material are from 0-1 wt %, more preferred0.01 to 0.2 wt %. Acidifiers may be incorporated to bring the pH of theproduct to the desired level, preferably the pH of the product is from 3to 10, more preferred 3.5 to 7. A suitable acidifier is for examplelactic acid or citric acid.

The spread may further containing small particles such as herbs andvegetables. The total level thereof will generally be less than 10 wt %.

Spreads of the invention will generally comprise fairly high levels ofwater, say from 75 to 99.9 wt % of the composition, more preferred 80 to99.5 wt %, most preferred 85 to 99 wt %. Water may be incorporated assuch, or as part of the other ingredients such as milk etc. Spreads ofthe invention are water-continuous in the sense that they comprise acontinuous aqueous phase. Water-continuous spreads can readily bedistinguished from fat-continuous spreads by virtue of conductivitymeasurements.

Spreads of the invention can suitably be used as bread spreads toreplace e.g. margarine or halvarine, but they can also suitable be usedas flavoured spread, for example cheese spreads, meat spreads, nutspreads, sweet spreads or vegetable spreads.

Spreads of the invention are preferably prepared by first preparing theinternal W/O phase with optionally fat soluble flavours, followed bydispersing this in the external water phase.

The invention is now illustrated by the following limitative example.All parts and percentages are taken by weight unless otherwiseindicated.

EXAMPLE 1

A W/O/W spread was prepared containing 87.5 wt % of external water phaseand 12.5 wt % of internal (W/O) phase. The internal phase consisted of a60:40 mixture of water emulsified in rapeseed oil (containing 0.1 wt %fat soluble flavour). The total fat level of the product was hence 5 wt%.

For comparison (COMP1) the same external phase was used at 95 wt % incombination with 5 wt % flavoured rapeseed oil to form a O/W spread.

For comparison (COMP2) the same external phase was used at 87.5 wt % incombination with 12.5 wt % flavoured rapeseed oil to form a O/W spread.

The composition of the external phase was:

    ______________________________________                                        Ingredient      Percentage (w.w.)                                             ______________________________________                                        Salt            1                                                             Gelatin (270 Bloom)                                                                           3                                                             NSCC 6110*      10                                                            Water           85                                                            Sodium caseinate                                                                              1                                                             ______________________________________                                    

The composition of the internal phase according to the invention was:

    ______________________________________                                        Ingredient       Percentage (w.w.)                                            ______________________________________                                        water            57.9                                                         rape seed oil (low erucic)                                                                     40                                                           Admul WOL        2                                                            Flavour (fat soluble)                                                                          0.1                                                          ______________________________________                                         *NSCC 6110 is a maltodextrin ex National Starch & Chemical Corporation        with a DE = 7.                                                           

The composition was prepared by the procedure described below:

The internal phase is prepared by mixing the emulsifier and oil atelevated temperature (50-100° C.) followed by adding the water undershear. A W/O emulsion is formed. The ingredients of the external aqueousphase are then added and the mixture is cooled in scraped surface heatexchangers. The resulting product is a W/O/W spread.

The comparative products were prepared by mixing the oil with theingredients of the external phase followed by cooling in scraped surfaceheat exchangers. The resulting product is a O/W spread.

When the appearance of the products was compared, it appeared that the5% fat product of the invention had an appearance similar to the 12.5%fat comparative product (COMP2) and less similar to the 5% fatcomparative product (COMP1). Also, surprisingly, the product of theinvention had a flavour/salt release which was slower than either theCOMP1 or the COMP2 product and was similar to the flavour/salt releaseof a commercially available 25% fat product (GOLD LOWEST marketed in theUK). The product according to the invention was an excellent plasticspread of good texture, mouthfeel and theological properties which didnot tear bread upon spreading. Moreover the fatty phase was based onhighly unsaturated triglycerides (low erucic rapeseed oil).

The rheological data of the products prepared are tabulated below:

    ______________________________________                                        Sample    Max. stress  Yield strain                                                                            Stress ratio                                 ______________________________________                                        5% fat    4.7 kPa      0.17      0.89                                         12.5% fat 4.2 kPa      0.17      0.91                                         Comparison                                                                              3.9 kPa      0.15      0.87                                         5% fat                                                                        ______________________________________                                         Yield strain equals strain occurring at maximum stress.                       Stress ratio equals ratio of plastic and maximum stress.                 

EXAMPLE 2

The procedure described in Example 1 was followed for preparing a spreadcontaining 10 wt % fat. There was one difference in procedure namelythat after the water had been added shear was applied at a level of 10⁴kPa in a standard dairy homogenizer. The comparison was also prepared bythe technique of Example 1.

The composition of the external phase was:

    ______________________________________                                        Ingredient      Example  Comparison                                           ______________________________________                                        NSCC 6110       9        9                                                    Gelatin 250 Bloom                                                                             2.7      2.7                                                  Salt            0.54     0.54                                                 Potassium-sorbate                                                                             0.18     0.18                                                 β-Carotene 0.045    0.045                                                Sodium caseinate                                                                              1.0      0.54                                                 Rape seed oil   --       10                                                   (low erucic)                                                                  Internal phase  25       --                                                   Flavour         0.262    0.262                                                Water           61.27    76.73                                                ______________________________________                                    

In the case of the spread according to the present invention an internalphase was prepared and used having the following composition:

    ______________________________________                                        Ingredients       Percentage (w.w.)                                           ______________________________________                                        Rape seed oil (low erucic)                                                                      40                                                          Admul WOL         3%                                                          Salt              0.6%                                                        Potassium sorbate 0.13%                                                       Water             56.27                                                       ______________________________________                                    

The water-in-oil emulsion was then prepared by the standard procedureoutlined above, homogenized at 10,000 kPa and then added to the externalphase in a ratio of three parts of external phase to one part internalphase. The stress, strain and ratio parameters of the product accordingto the invention were: maximum stress 3.5 kPa, strain at maximum stress0.15 and ratio of plastic and maximum stress 0.91. It was furtherestablished that the product according to the invention had a bettervisual appearance (opacity) and better salt and flavour release.

EXAMPLE 3

The procedure described in Example 1 was followed for preparing a spreadcontaining 2 wt % fat.

The composition of the external phase was:

    ______________________________________                                        Ingredient                                                                              Example    Comparison 1                                                                             Comparison 2                                  ______________________________________                                        Paselli SA2*                                                                            12.0       12.0       12.0                                          Gelatin   3.0        3.0        3.0                                           (270 Bloom)                                                                   Sunflower --         2          5                                             oil                                                                           Internal  5.0                                                                 phase                                                                         Na-caseinate                                                                            1.0        1.0        1.0                                           Salt      1.4        1.4        1,4                                           K-sorbate 0.12       0.12       0.12                                          Water     77.38      80.38      77.38                                         Flavour   0.1        0.1        0.1                                           ______________________________________                                         *Paselli SA2 is according to recent information of the manufacturer a         hydrolyzed starch/maltodextrin DE = 2.9.                                 

With respect to the procedure of Example 1 there was one difference inthis procedure namely that after the water had been added shear wasapplied at a level of 10⁴ kPa in a standard dairy homogenizer.

The composition of the internal phase was:

    ______________________________________                                        Ingredient     Percentage (w.w.)                                              ______________________________________                                        Sunflower oil  40                                                             Admul WOL      2.0                                                            Salt           0.9                                                            Potassium sorbate                                                                            0.12                                                           Water          56.88                                                          Flavour        0.1                                                            ______________________________________                                    

The rheological parameters of this spread according to the presentinvention were similar to those of Example 1. The appearance of theproduct according to the invention was similar to the comparisoncontaining 5% oil. The. comparison containing 2% fat had a watery,translucent appearance and the salt and flavour release of the productaccording to the present invention was slower than of the comparisons.

I claim:
 1. A water-continuous spread containing from 0.1 to 20 wt. % offat, said spread being a W/O/W emulsion comprising hydrolysed starchwith a DE of 1-6 in the external phase at a concentration above itscritical gelling concentration, said spread having a stress strainrelation with a maximum stress occurring at a strain of 0.01-1, themaximum stress at this strain being 0.1 to 100 kPa and with a ratio ofplastic stress and the maximum stress of 0.1 to
 1. 2. Spread accordingto claim 1 comprising from 0.1 to 30 wt % of hydrolysed starch andgelatin taken together.
 3. Spread according to claim 2 wherein thegelatin has a bloom value of 200 to
 270. 4. Spread according to claim 1,wherein the external water phase constitutes 20 to 99 wt %, morepreferred 50 to 98 wt %, most preferred 70 to 97 wt % of the product. 5.Spread according to claim 1, wherein the level of fat is from 0.2 to 15wt %, more preferred 0.5 to 10 wt %.
 6. Spread according to claim 1,wherein the dispersed phases constitute from 1 to 80 wt % of the productand wherein the ratio fat to water in the dispersed phase is from 50:1to 1:50.
 7. Spread according to claim 1 wherein the spread contains from0.01 to 2 wt % of an emulsifier system.
 8. Spread according to claim 1wherein the hydrolysed starch is a maltodextrin with a DE from 2 to 4.9. Spread according to claim 1 wherein said spread has a fat level of0.5 to 10 wt % calculated on the total composition.
 10. Spread accordingto claim 1 wherein the fat phase is based on highly unsaturatedvegetable oils.